1. Field of the Invention
The present invention relates to an electronic apparatus with an operation button in which a decorative panel covers the operation button placed on a front panel except for an operating portion of the operation button so that the operating portion can be pushed to operate an internal switch. In particular, the present invention relates to a practical electronic apparatus which facilitates an operation of mounting the operation button to reduce the number of parts required, the electronic apparatus being capable of using the simple structure to prevent the operation button from being excessively pushed into the electronic apparatus during a button operation.
2. Description of the Related Art
Japanese Patent Laid-Open Publication No. 2000-165064 (patent document 1) proposes a “mounting structure for a key pushing device” which is a case mounting structure for an operation button placed in a radio apparatus such as a cellular phone. With this conventional technique, a pedestal is formed inside the case so that the operation button can be mounted on the pedestal. An engaging pawl is engaged with an engaging portion formed in the case; the engaging pawl is composed of a generally L-shaped elastic member and formed on a bottom surface portion of the operation button. The bottom surface portion of the operation button is mounted on the pedestal. Thus, the operation button is fixedly positioned by the engaging pawl, the engaging portion, the pedestal, and a stopper portion without using any tightening means such as screwing or fusion; the stopper portion is provided on the pedestal.
Further, Japanese Patent Laid-Open Publication No. 2000-299567 (patent document 2) proposes a “mounting structure for a series of pushbutton pieces” which is used to mount operation buttons used for an electronic apparatus such as a television, on a front panel. With this conventional technique, one side of the series of operation buttons connected together is inserted and fitted around a guide rib formed on the inner surface side of the front panel, a positioning pin, and a positioning rib. The other side of the series of operation buttons is inserted and fitted around an end of a printed circuit board. Thus, this mounting structure is fixedly positioned without using any tightening means such as screwing or fusion.
With the above conventional techniques, for example, with the patent document 1, the need for extra time and effort may arise because the operation button is mounted inside the case. That is, when a defect such as damage occurs in the operation button, which must thus be replaced with a new one, it may be necessary to disassemble the radio apparatus, replace the operation button, and then recover the disassembled other members to their original state. Further, the pedestal, used to fix the operation button, is integrated with the case inside the case. This complicates the shape of a mold used to form the case, thus increasing the costs of the mold. Furthermore, the structure makes it difficult to reduce the sizes of the electronic apparatus such as the radio apparatus because, for example, the formation of the pedestal requires an extra internal space. With the patent document 2, when a defect such as damage occurs in the operation buttons, it may be necessary to disassemble the electronic apparatus, remove the printed circuit board, replace the operation button, and then recover the disassembled printed circuit board and other members to their original state. Further, since the mounting structure has no stopper portion that prevents the operation buttons from being excessively pushed, the lifetimes of the operation buttons are short unless the structure is provided with a separate stopper member. Or switches provided on the printed circuit board may be damaged. When a separate stopper member is provided to avoid the above situation, more parts may be required for the structure. The present invention provides an electronic apparatus with an operation button which has the following advantages. The mounting structure for the operation button is simplified to allow the operation button to be fixed to the front panel without increasing the costs of the mold or depending on tightening means such as screwing or fusion. The simple structure is used to prevent the operation button from being excessively pushed in, without the need to provide an additional separate member. The structure dispenses with the complicated operation of disassembling the electronic apparatus, replacing the operation button with a new one, and recovering the disassembled members to their original state even when the operation button becomes defective. This facilitates the operation of mounting the operation button and makes it possible to reduce the number of parts required.